Chapter 2 – Methodologies for Studying Bioactive Polysaccharides

TL;DR: This chapter first introduces the methods for isolation and purification of natural polysaccharides from various sources, and summarizes detailed methods for structure analysis and conformation evaluation.

Abstract: Polysaccharides extracted from different natural sources show important bioactivities, which are first affected by their natural resources. They are always present, together with various other components, and thus this chapter first introduces the methods for isolation and purification of natural polysaccharides from various sources. To be more specific, the bioactivities of polysaccharides are various, and they are highly dependent on the chemical structures and chain conformations of the polysaccharides. Then, this chapter summarizes detailed methods for structure analysis and conformation evaluation. Methods for structure analysis can be classified as chemical methods, instrumental methods, and biological method, while methods for evaluating conformations mainly involve light scattering and molecular modeling. Furthermore, the biological activities of polysaccharides can be investigated by animal studies and clinical trials, which are also described in this chapter. During biological events, the polysaccharides commonly act as immunomodulators or biological response modifiers which can augment host defense responses. Thus, this chapter finally includes the action mechanisms and interactions between polysaccharides and receptors. There are several major types of receptors, Toll-like receptors, mannose receptors, Dectin-1, Dectin-2, scavenger receptors (SR), and Type 3 Complement Receptor (CR3), etc. To sum up, the methodologies for studying the bioactivities of polysaccharides could provide us with different points of view for understanding the importance of polysaccharides.